Q. Some dogs greet my dog by sniffing noses and wagging tails, and then they suddenly nip her on the nose or muzzle. My dog gets very upset and barks at them. Other dogs greet her the same way but don't nip her. Then my dog starts playing with them.
My dog is friendly, but is now cautious when a dog greets her. She appears to be waiting to see if they are going to nip her. Why do some dogs do that to her?
A. In the canine social spectrum, there are dogs who prefer to be the Sniffer (top dog) when first greeting another, and not the Sniffee (second place). When two dogs approach, each moves and stands in certain ways, which in dog body language communicates whether they're a Sniffer or a Sniffee. Even between two dogs who both prefer to sniff first, there will be subtle differences in posture that help them determine which should sniff first in this situation.
You didn't mention your dog's age, but from your description it sounds like she may still be learning certain doggie social graces. Puppies usually learn social postures and rules from other dogs while growing up. If a pup, for some reason, reaches adolescence or adulthood without socializing much with dogs, she may be unskilled in appropriate social behavior. Failure to yield the right to sniff first can earn a corrective nip for an “uppity” pup or adolescent. The other dogs are teaching her to control her urge to greet them until she's observed their posture. She's now waiting to see what the other dog does, before rushing up to sniff noses, and that's an appropriate and polite behavior.